2024 Cedar S4 Physics Prelim P2

CEDAR GIRLS’ SECONDARY SCHOOL Preliminary Examination 2024 Secondary 4 CANDIDATE NAME CLASS INDEX NUMBER CENTRE/ INDEX NO / PHYSICS 6091/02 Paper 2 Structured Questions 23 August 2024 1 hour 45 minutes Candidates answer on the Question Paper. No Additional Materials are required READ THESE INSTRUCTIONS FIRST Write your name, class and index number in the spaces at the top of this page. Write in dark blue or black pen. You may use a HB pencil for any diagrams, graphs. Do not use staples, paper clips, glue, or correction fluid. Section A Answer all questions. Write your answers in the spaces provided. Section B Answer one question. Write your answers in the spaces provided. Candidates are reminded that all quantitative answers should include appropriate units. The use of an approved scientific calculator is expected, where appropriate. Candidates are advised to show all their working in a clear and orderly manner, as more marks are awarded for sound use of Physics than for correct answers. The number of marks is given in brackets [ ] at the end of each question or part question. For Examiner’s Use Paper 1 40 Paper 2 Section A 1 4 2 6 3 3 4 8 5 9 6 5 7 8 8 6 9 10 10 11 Section B 11 10 12 10 Deductions sf Total (P2) 80 Overall Total % This document consists of 19 printed pages. [Turn over

2 For Examiner’s Use Section A (70 marks) Answer all questions in this section. 1 Fig. 1.1 shows a water wheel used in a farm. Water entering at the top turns the wheel about the hub. Fig. 1.1 The water wheel moves in a circular path at a constant speed of 2.5 m/s. (a) (i) State the change in speed of point C as it moves to position D. change in speed = …………………. [1] (ii) Determine the magnitude of the change in velocity of point C as it moves to position D. change in velocity = …………………… [1] (b) A Cedarian suggest that the water in the wheel undergoes acceleration. Discuss if she is correct. ………………………………………………………………………………………………….. ………………………………………………………………………..………………………… …………………………………………………………………………………………… [2] water in hub spokes D C L

3 [Turn over For Examiner’s Use 2 (a) A girl of weight 550 N is playing on a see-saw with her brother. Fig. 2.1 shows her brother of weight W sitting 1.1 m to the right of the balance point. Fig. 2.1 (not to scale) The see-saw is balanced when the girl sits 0.86 m to the left of the balance point. (i) Determine the weight of the brother, W. weight = ……………..... [2] (ii) The girl and her brother slide an equal distance along the see-saw away from each other at the same time. Describe and explain what happens. ……………………………………………………………………………………………..…… ……………………………………………………..…………………………………………… …………………………………………………………………………………………… [2] (b) Fig. 2.2 and Fig. 2.3 below illustrate the rest position and the displaced position of a toy respectively. G is the centre of gravity of the toy. Fig. 2.2 Fig. 2.3 Explain why the toy returns to its rest position when displaced and released from the position as shown in Fig. 2.3. …………………………………………………………………………………..……………… ……………………………………………………………………………………………..…… …………………………………………………………………………………………… [2] brother balance point girl 0.86 m 1.1 m 550 N W • G 0.44 m 0.2 m

4 For Examiner’s Use 3 Fig. 3.1 shows a mercury manometer. The left arm of the manometer contains some trapped gas. The density of mercury is 13 600 kg / m3. The gravitational field strength g is 10 N / kg. Fig. 3.1 The atmospheric pressure is 76.0 cm Hg. (a) Calculate the pressure of the trapped gas in SI unit. pressure = ………………… [2] (b) A small hole is made in the left arm of the manometer such that the trapped gas can escape to the surroundings. In Fig. 3.2 indicate the new mercury levels in both arms of the manometer after some time. Fig. 3.2 [1] trapped gas mercury hole

5 [Turn over For Examiner’s Use 4 Fig. 4.1 shows a shallow tank viewed from above. The depth of the water is different in the two parts of the tank. Fig. 4.1 shows the crests and the troughs of a wave that pass from left to right. Diagram is not drawn to scale. Fig. 4.1 (a) (i) Name the phenomenon observed above that is a characteristic of a wave: ………………………………………………….……….................................................. (ii) Based on Fig. 4.1, state and explain what happened to the speed of the wave as it passes from left to right. [1] …………………………………………………………………………………………… …………………………………………………………………………………………… …………………………………………………………………………………………… …………………………………………………………………………………………… [2] (b) The speed of the wave in the left-hand part of the tank is 0.39 m/s. (i) Using information from Fig. 4.1, determine the frequency of the wave. frequency = ………………… [2] 2.6 cm boundary trough crest 33° 45°

6 For Examiner’s Use (ii) Determine the speed of the wave in the right-hand side of the tank. speed = ………………… [3]

7 [Turn over For Examiner’s Use 5 In the circuit shown in Fig. 5.1, a battery of e.m.f. 6.0 V is connected to a 60 Ω resistor, lamp L and a switch. Fig. 5.1 The lamp L is marked 6.0 V, 0.90 W. (a) When the switch is closed, calculate (i) the current supplied by the battery, current=…………….. [2] (ii) the amount of charge supplied by the battery in a time of 1.50 hours. amount of charge=…………….. [2] (b) A light-dependent resistor (LDR) is added to the circuit where it is in series with the lamp as shown in Fig. 5.2. Fig. 5.2 When the switch is closed, light from the lamp falls on the LDR. The current supplied by the battery changes. Describe and explain the changes to the brightness of lamp L when the switch is closed. …………………………………………………………………………………………………… …………………………………………………………………………………………………… …………………………………………………………………………………………… [2] 6.0 V switch 60 Ω L 6.0 V 60 Ω L LDR switch

8 For Examiner’s Use (c) A student investigates the use of devices in setting up a fire alarm system. The following components are connected to a d.c. power supply as shown in Fig. 5.3: • two 10 kΩ resistors, • a light-dependent resistor with resistance 10 kΩ in the dark and 10 Ω in bright light. • a negative temperature coefficient (NTC) thermistor with resistance 10 kΩ in low temperature and 10 Ω in high temperature, • a bell. Fig. 5.3 The system is initially in a cold and dark environment. The bell will only sound under high temperature and bright light conditions. (i) On Fig. 5.3, draw in two resistors, one light -dependent resistor and one thermistor in the spaces. [1] (ii) Using your answer to (c)(i), describe and explain the operation of the fire alarm system. ……………………………………………………………………………………… ……………………………………………………………………………………… ……………………………………………………………………………………… ……………………………………………………………………………………… [2] d.c. power supply bell

9 [Turn over For Examiner’s Use 6 Fig. 6.1 shows a solenoid connected to an ammeter. Fig. 6.1 The S-pole of a permanent magnet moves into the left-hand end of the solenoid. The ammeter reading shows that there is a small positi